1. Field of the Invention
The present invention relates to an electron beam processing device for irradiating electron beams onto a substance and thereby subjecting it to various treatments, and particularly, relates to an electron beam processing device for curing an interlayer insulating film of a semiconductor device, which is called as SOG (Spin On Glass) film on a wafer, and forming film on other substances, and the like.
2. Description of the Related Art
FIG. 10 shows an example of a conventional electron beam processing device.
The electron beam tube 1 is connected to a high voltage power source which is not shown as a drawing, and has a function to irradiate electron beams onto a substance 6 in the processing chamber 2. The electron beam tube 1 has a lid part 3 and window 4, and the lid part 3 is made, for example, from silicon and provided to cover an opening of the electron beam tube 1. The lid part 3 has an opening 31 for allowing the electron beam, which is radiated from the electron beam tube 1 toward the processing chamber 2, to pass therethrough.
The window 4 which is covering this opening 31, is made from a material permeable to an electron beam, and is formed in a plurality. This window 4 is made, for example, from silicon and is formed of a thin film of several xcexcm. Then, an irradiation part of the electron beam tube is formed of the lid part 3 and the window 4.
The substance 6 is placed on a heating plate 5.
According to this type of electron beam processing device, the substance 6 is irradiated with the electron beam which is radiated from the electron beam tube 1, and is processed effectively in a short time. Further, the substance 6 is processed more effectively by heating the substance on the heating plate 5.
Nevertheless, a conventional electron beam processing device has a problem that contaminants adhere to the window 4 and a drawback that the temperature of the window 4 rises high.
Specifically, when electron beams are irradiated onto an organic film such as a resist or the like as the substance, volatile contaminants are generated from this organic film, and the contaminants adhere to the irradiation part of the electron beam tube 1, particularly to the window 4. And when such contaminants adhere to the window 4, there arises a problem that the window 4 is oxidized or carbonized, and thereby the mechanical strength thereof is weakened, and, as a result, the window may become damaged.
Further, when such contaminants adhere to the window 4, there arises a problem that the energy of the electron beam passing through the window 4 is absorbed by such contaminants, and, as a result, the temperature of the window 4 rises high, and thereby the window may become damaged.
In addition, although not shown as a drawing, there are cases when process gas such as chlorine (Cl), fluorine (F) or the like is supplied during the processing, the silicon of the window 4 may be etched by these gases. Thus, there arises a problem that the mechanical strength of the window 4 is weakened, and thereby the window may become damaged.
Further, the heat for heating the substance 6 also transfers to the window 4 and thereby the temperature of the window 4 rises high. And, since the window 4 is formed of a thin film so as to effectively radiate electron beams, there arises a problem that the window 4 may be damaged in a few hours if the temperature of the window exceeds, for example, 400xc2x0 C.
Moreover, when the lid part 3 is heated together with the window 4, gases are released from the various members arranged within the electron beam tube 1. These members, for example, are metal materials which are provided for generating electron beams and glass bodies structuring the outer periphery of the electron beam tube 1. And, when the gases are released, the gas pressure in the electron beam tube 1 rises high, and thereby electric discharge may be generated between the respective members in the electron beam tube 1, and, as a result, there arises a problem that a desired output of an electron beam can not be obtained.
An object of the present invention is to provide, in consideration of the various problems described above, an electron beam processing device capable of preventing contaminants from adhering to the irradiation part, particularly the window, which is exposed in the processing chamber of the electron beam tube, as well as controlling the rise of the temperature of this irradiation part.
In order to solve the aforementioned problems, the present inventor has adopted the following means.
The first means is a processing device characterized in that an irradiation part of an electron beam tube is disposed in a processing chamber and irradiates an electron beam onto a substance placed in the processing chamber, wherein the irradiation part is composed of a lid part with an opening for allowing the electron beam to pass therethrough and a window which covers the opening and has a transmission part permeable to the electron beam, and further, a cooling block is arranged in contact with a part of the irradiation part excluding the transmission part.
The second means is characterized in that means for spraying a cooling gas toward the window is provided in addition to the first means.
The third means is a processing device characterized in that an irradiation part of an electron beam tube is disposed in a processing chamber and irradiates an electron beam onto a substance placed in the processing chamber, wherein an inert gas spraying part for spraying inert gas toward the irradiation part and an outlet for such inert gas are provided near the irradiation part.
The fourth means is a processing device characterized in that an irradiation part of an electron beam tube is disposed in a processing chamber and irradiates an electron beam onto a substance placed in the processing chamber, wherein the processing chamber is composed of a first processing chamber which stores the irradiation part of the electron beam tube and has an inlet for inert gas, a second processing chamber which stores the substance placed and has an outlet for such inert gas, and the first processing chamber and second processing chamber are separated by a partition which has opening for the electron beam and inert gas.
The fifth means is characterized in that a gas inlet for flowing process gas necessary for processing the substance is provided at the lower side in the processing chamber, said process gas is introduced after the inert gas passed near the irradiation part of the electron beam tube.